The Program in Hematopoietic Cell Transplantation and Immune Reconstitution is a multidisciplinary effort aimed at developing a better understanding of the biological mechanisms underlying both autologous and allogeneic hematopoietic cell transplantation (HCT). Major themes of research include developing mechanistic insights into the underlying principles of stem cell engraftment, graft vs. host disease, graft vs. tumor reactions and immune reconstitution. Translation of novel concepts to the clinic derived from these more basic studies is of central importance. These goals are achieved by engaging a dynamic group of 19 investigators from four Departments supported by Program Project (two POls), investigator initiated (17 ROls), clinical trials network (U01), training (T32 and three K awards) and Foundation grants. Using the concept of translational research where new concepts and ideas are developed in the laboratory and extended to the clinic, as well as insights from the clinic with extension to the laboratory, novel avenues of research and strategies for intervention have been and continue to be explored. Since 2000, over 180 publications relevant to the goals of the Program have been published in peer-reviewed journals. This Program enlists basic scientists, physician-scientists and clinician investigators centered upon the over-riding goal of improving outcomes for patients undergoing HCT. Our vision is to explore the major mechanisms of successful transplantation including engraftment of hematopoietic stem cells, graft-vs.-tumor and graft-vs.-host reactions and enhancement of immune reconstitution through laboratory-based projects with extension to the clinic through mainly investigator initiated clinical trials. Clinical strategies have and are being developed based upon laboratory investigations to probe mechanisms of the major cellular populations including hematopoietic stem cells, myeloid and lymphoid progenitor cells, NK, T, NK-T and antigen presenting cells. This Program extensively interacts with both basic and translational investigators from a number of different Programs and is supported by all Cancer Center Shared Resources to provide a rich fabric of discovery and clinical translation.